Refrigerating apparatus



March 13, 1934. R K MILLER 1,950,510

REFRIGERATING APPARATUS Original Filed Oct. 31, 1928 3 Sheets-Sheet 1 March 13, 1934. R. K. MILLER REFRIGERATING APPARATUS ori i'na'i E'iled Oct. 31, 1928 3 Sheets-Sheet 2 March 13, 1934. R, K MLLE 1,950,510

REFRI GERAT ING APPARATUS Original Filed Oct. 31, 1928 3 Sheets-Sheet 3 Patented Mar. 13, 1934 UNITED sTA'rss PATENT. OFFICE 1,950,510 REFRIGERATING APPARATUS Ralph K. Miller, Dayton, Ohio, assignor to Frigidaire Corporation, Dayton, Ohio, a corporation of Delaware Application October 31, 1928, Serial No. 316,173

Renewed April 19, 1933 20 Claims. (Cl. 62-115) maintaining the temperature of the compressor within certain limits.

Another object of this invention is to provide a refrigerating apparatus with an air-cooled compressor and condenser and provided with automatic means for regulating the flow of air past the compressor.

Another object of this invention is to provide a refrigerating apparatus a portion of which includes a compressor of the gear type in which the gears intermesh in such a manner thatintermediate stages are providedin the compression.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig, l is a view partly in elevation, partly in section and partly diagrammatic of a refrigerating apparatus embodying features of this invention;

Fig. 2 is a horizontal cross-sectional view,

' somewhat enlarged, ofa portion of the'compressor, taken along the line 2-2 of Fig. 3, with additional parts not shown in Fig. 3.

Fig. 3 is a top elevation of a part of the compressor with the upper plate 61 removed;

Fig. 4 is a top plan view of a portion of the compressor casing;

Fig. 5 is a side view in elevation of Fig.4 with a part in section taken along the line 5-5 of Fig. 4;

Fig. 6 is a top view of the lower bearing plate of the compressor;

Fig. '7 is a cross-section taken along the line 7-7 of Fig. 6;

Fig. 8 is a cross-section taken along the line 8-8 of Fig. 6; Fig. 9 is a top elevation of the upper bearing plate of the compressor;

Fig. 10 is a cross-sectional view taken along the line 10-10 of Fig. 9;

Fig. 11 is across-sectional view taken along the line 11-11 of Fig. 9; and Fig. 12 is a cross-section of a portion of the compressor casing taken along the line 12-12 of Fig. 3.

A refrigerating apparatus embodying features of this invention may comprise in general a re-' frigerant liquefying unit and a refrigerant evaporating unit generally designated as 21.

The refrigerant, and possibly the lubricant, travel in closed cycles between the refrigerant liquefying unit 20 and the refrigerant evaporating unit 21 through the pipes 22 and 23. The refrigerant, in a liquid condition, may travel through the pipe 22 into the refrigerant evaporating unit 21 and from thence the refrigerant in an evaporated condition may return through the pipe 23 to the refrigerant liquefying unit 20. The unit 21 may be of any suitable type, and may be of the type shown in the patent to R. G. Osborn, 1,556,708, dated October 13, 1925.

The evaporated refrigerant passing through the pipe 23 may enter into a chamber 24- within the refrigerant liquefying unit. From thence it may pass through a passage and pipe 25 into a compressor intake chamber 26. From thence it may pass through the compressor 27 into a lubricant chamber or well 28. From thence it may pass, through suitable conne 310115 to be described, into the condenser 29 where it is liquefied and delivered in a liquid condition to the liquid refrigerant receiver 30. From this receiver 30 itmay pass through a fitting 31 into the pipe 22 and from thence to the refrigerant evaporating unit 21.

The lubricant may be circulated in a closed cycle also. This cycle may follow the refrigerant cycle, or the lubricant may be separated from the refrigerant after passing through the compressor and may be returned to the compressor intake in a closed cycle partly separate from the cycle of the refrigerant. In this particular embodiment the two cycles are coincident, the compressor being maintained in a lubricant flooded condition by the lubricant in the well 28 and by the lubricant returning to the intake. of the compressor.

The refrigerant liquefying unit 20 may include the compressor 27, the lubricant chamber or well 28, the condenser 29, the receiver 30, a cooling fluid medium circulating means 32 and a prime moving means 33. The cooling fluid medium may be air, and when such is the case, the circulating means 32 may be a fan. The prime moving means 33 may be an electric motor. If the cooling fluid medium is air, it. may enter through openings 35 at the bottom of a casing 36. A portion of the air may rise upwardly past the receiver 30 and the condenser 29 and. may flow through a passage 37 and an opening 38 to the fan 32. From thence it may pass out of the casing through openings 39. Anotherportion of the air may flow from the openings 35 through a .eration of heat by the compressor.

condenser 29. A thermostat 43 may regulate the circulation of the cooling fluid medium past the compressor, for instance, by moving a valve 44 relatively to the passage 40. Thus when the compressor 27 becomes heated the thermostat 43 opens the passage 40 to a greater extent and thus provides a greater amount of cooling fluid medium in order to reduce the temperature of the compressor 27. The compressor may be provided with fins 45 in order to enhance'the cooling action of the air as it passes; the compressor. By lowering the temperature of the compressor in proper relation to the character of the lubricant greater efliciency is obtained. For example it is desirable to employ a lubricant or oil in the,

i system which does not become too thin to properly seal the gears of the compressor upon gen- Normally an oil of a suitable character for such purposes as explained is very heavy or viscous at room temperatures, say, between 70 and F., and this oil tends to prevent the compressor from gaining momentum upon starting thereof. Therefore in order to thin the oil immediately upon initial operation of the compressor to render the oil capable of effectively sealing the gears of the compressor while at the same time permitting flow of refrigerant along with oil through the compressor as wellas permit the compressor to attain a desirable speed or momentum at which it functions efficiently, the thermostat 43 is adjusted to maintain the valve 44 in closed position at normal room temperatures. Thus cooling of the compressor by air, circulated by the fan 32, is prevented during the initial operation of the compressor. The compressor therefore immediately generates heat until a temperature has been attained in the compressor sufficient to affect the thermostat 43.- Obviously the thermostat 43 then controls the position of the valve 44 relative to the passage 40 in the shield or cowling 41 to regulate the amount of air circulating in contact ,with the compressor to maintain the compressor, and consequently the oil contained therein, at a desired temperature so as to obtain maximum efficiency from the compressor.

The chamber 24, which receives the evaporated refrigerant from the pipe 23, may be the seal chamber for the shaft seal. Thus a sylphon 46 may be hermetically and slidingly connected to the portion 47 of the compressor casing. The other end of the sylphon 46 may be hermetically connected to the bearing member 48 of the shaft 50. The sylphon 46 rotates with the shaft 50 and the upper end of the sylphon has a sliding contact through the medium of a sealing member 51, secured to the sylphon, with the sealing member 52 secured to the member 47. The lower portion of the member 48 has a sliding contact with the member 53 of the compressor casing. It is thus. seen that the chamber 24 is under the pressure of the evaporated refrigerant, since the refrigerant passes through said chamber on its way from pipe 23 to passage 25.

The refrigerant after passing through the passage and pipe 25 into the chamber 26 may enter the compressor 27 through an opening 55 in the lower bearing plate '56 of the compressor and through a corresponding opening, not shown, in the supporting plate 5'7 which is interposed between ,the chamber 26 and the compressor 27. Fromthe inlet 55 the refrigerant and the lubricant are taken as indicated by the arrows in Fig. 3 to two intermediate compression chambers 58 and 59. From thence the refrigerant and the lubricant are taken by the gears to the notch 69 in the casing 72 and to the outlet 60 in the upper plate 61. As the refrigerant and the lubricant pass out of the outlet 60, the refrigerant bubbles up through a body '62 of lubricant in the chamber 28. This body 62 of lubricant tends to separate to some extent the refrigerant from the lubricant. The refrigerant, with some lubricant, passes through openings 64 and passages 65 to parallel coils of the condenser29. The coils may be concentrically and spirally wound around inside of the casing 36 so that the refrigerant flows downwardly in two spiral paths which join in the circular receiver 30. The condenser may, of course, be made with a single spiral path instead of two parallel paths. The tubing of the condenser 29 may be provided with fins 66, if desired.

The lubricant may follow the refrigerant in the closed cycle through the pipes 22 and 23 and thence back to the inlet chamber 26. Another type of lubricant circulation in a closed cycle may be obtained merely by the head of lubricant created by the body of lubricant 62 which maintains the compressor in a floodedcondition so that the lubricant merely has a tendency to flow back to the inlet of the compressor and thus the backward seepage of the lubricant within the pump creates a closed cycle for the lubricant. An auxiliary circulating circuit may also be provided for the lubricant which may be cir-- culated from the body 62 back to the inlet chamber 26 independently of the refrigerating cycle. Such auxiliary circulating means may be somewhat of the character disclosed in the copending application of Ralph K. Miller and Robert M. Getchell, Serial No. 315,988, filed October 30, 1928, for Refrigerating apparatus, merely by the addition of an auxiliary lubricant pump to circulate the lubricant from the well 28 to a lubricant cooling coil, not shown, and from thence to the chamber 26. Any type of lubricant pump drivingly connected to the mechanism may be used, preferably of less capacity than the main compressor 27.

The compressor 27 may include two pairs of gears 70 and 71. These pairs of gears may be placed within a casing .72 which may be provided with an'upper bearing plate 61 and with a lower bearing plate 56. These members may be placed within an outer compressor casing 73 which may include a lower funnel-shaped member 74 hermetically connected to an upper cap 75 by means of the bolts 76. The cap member 75 may be provided with the casing member 47 which forms the seal chamber 24 heretofore described. The funnel-shaped member 74 may be provided with radial fins 77 and may be connected at its lowerend with the platev57 and with a cup-shaped member 78 to form the inlet chamber 26. Bolts 79 or the like may be used for joining the members 74, 57 and 78.

,Pipe 28 maybe connected to a passage 80 (Fig. 4) in the cap member 75. The passage 80 may lead to the chamber 24. The passage 25 may be also embodied in the cap 75 and may terminate in a fitting 81 (Fig. 1) which joins the two portions of the passage and pipe 25. If desired a check valve 82 may be interposed between the pipe 25 and the chamber 26.

The cap member 75 may be provided with radial extensions 83' which may be joined to 36 may be secured by means of bolts 85. An upper cap-shaped casing 86 may be connected to the ring 84' and may form the extension of the casing 36 for the guidance of the air to the outlet opening 39. If desired, a plate 87 may be interposed between the ring 84 and the casing 86 in order to guide the air to the center of the fan member 32.

The electric motor 33 may be started and stopped automatically. A method of doing this may be by connecting an expansible bellows 88 by means of a pipe 89 with the pipe 23. The bellows 88 may control the snap switch 90 .for making or breaking the electric circuit 91 leading to the motor 33.

The drive shaft 50 may be extended upwardly with a central opening 92 through which lubracant may be introduced to the sealing members 51 and 52 from the top of refrigerant liquefying member. The drive shaft of the compressor may be connected by a fitting 101 with the shaft 50. The drive shaft 100 may be connected to any one of the gears and in this particular embodiment is connected to the gear 102. The gears 102 and 103 comprise the low pressure pair 70, while the gears 104 and 105 may comprise the high pressure pair 71. The two pairs 70 and 71 may have at least one gear each intermeshing with at least one gear of the other pair. Thus the gear .102 of the pair 70 intermeshes with the gear 105 of the pair '71. It is thus seen that the refrigerant is given a low stage of compression by the pair 70 which deliver the refrigerant in two streams to the intermediate compression chambers 58. From thence the high pressure pair 71 deliver the refrigerant in two streams to an outlet notch 69 and from thence the refrigerant may flow to the outlet 60 in the upper plate 61.

The teeth of the gears may be slanted, and preferably the gears may be of the herringbone variety. In order to provide relief for the lubricant which is entrapped in the intermeshing teeth, the plates 56 and 51 may be provided with relief passages 107 and 108. The passages 10'? receive the entrapped lubricant from the gears 102 and 103 and deliver the same to the gear 105. The relief passage 108 receives the entrapped lubricant from the gears 102 and 105 and delivers it to the gear 104. By this construction the two chambers of intermediate compression are interposed between the refrigerant inlet and all of the intermeshing contacts with the exception of the contact between the gears 102 and 103. A large part of the compression lost is due to the backward slippage between the intermeshing contacts. In a compressor of this character this backward slippage is arrested in the intermediate compression chambers 58 and 59 and thus a. large part of the loss is avoided. The relief passages 10'? and 108 may be drilled in the plates 56, and 61, after which the ends of the passages may be sealed by plugs 110. Thus providing U-shaped passages between the intermeshing gears and the pumping gears. The. shafts 100 and 112 for the gears may be received in openings 113 in the plates 56 and 61. Any means may be used for securing the plates 56, 5'7 and 61, and the casing 72 together. A convenient way of doing this is by providing shoulders 114 in the casing 74 which hold the members of the pump together. Of course, bolts passing through the plates 56, 5'7

' and 61, and casing 72 may be used to augment,

or in lieu of, the shoulders 114. For this purpose openings 115 may be provided in these members.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a refrigerating apparatus, a closed circuit which includes a rotary gear compressor through which the refrigerant and the lubricant are circulated, a condenser through which the refrigerant is circulated by said compressor, means for circulating a cooling fluid medium in contact with said compressor and said condenser, and thermostatic means responsive to the temperature of said compressor for shielding the compressor from the circulation of the cooling fluid medium in contact with said compressor.

2. In a refrigerating apparatus, a closed circuit which includes a compressor through which the refrigerant and the lubricant are circulated, a condenser through which the refrigerant is circulated by said compressor, means for circulating air in contact with said compressor and said condenser, and thermostatic means responsive to the temperature of said compressor for blocking the circulation of the air in contact with said compressor.

3. In a refrigerating apparatus, a closed cir cuit which includes a compressor through which the refrigerant and the lubricant are circulated, a condenser through which the refrigerant is circulated by said compressor, means for circulating air in contact with said compressor and said condenser, and thermostatic means responsive to the temperature of said compressor for shielding the compressor from the circulation of the air in contact with said compressor.

4. In a refrigeratingapparatus, a closed circuit which includes a compressor through which the'refrlgerant and the lubricant are circulated, a condenser through which the refrigerant is circulated by said compressor, means for circulating air in contact with said compressor and said condenser, and thermostatic means responsive to the temperature of said compressor for blocking the circulation of the air in contact with said compressor.

5. In a refrigerating system, a compressor, a condenser connected to the compressor, an enclosure about said compressor and condenser, a cowling about said compressor, means for circulating a cooling fluid medium through the enclosure and said cowling, and means for regulating the flow of cooling fluid medium through said cowling.

6. In a refrigerating system, a compressor, a condenser connected to the compressor, an enclosure about said compressor and condenser, a cowling about said compressor, means for circulating a cooling fluid medium through the enclosure, and thermostatic means responsive to the temperature of said compressor for regulating the circulation of cooling fluid mediumv through said cowling.

7. In a refrigerating apparatus, a closed circuit including an evaporator, a compressor through which a refrigerant is circulated, a condenser interposed insaid closed circuit between the evaporator and the compressor for receiving refrigerant discharged from said compressor, means for circulating a cooling fluid medium in contact with said compressor, a valve ISO for regulating the flow of the cooling fluid medium in contact with said compressor, and thermostatic means responsive to the temperature of the compressor for actuating said valve.

8. In a refrigerating apparatus, a closed circuit including an evaporator, a compressor through which a refrigerant is circulated, a condenser interposed in said closed circuit between the evaporator and the compressor for receiving refrigerant discharged from said compressor, means for circulating a cooling fluid medium in contact with said compressor, a movable shielding means for varying the flow of the cooling fluid medium in contact with said compressor, and a thermostat for moving the shielding means in response to the temperature of the compressor.

9. In a refrigerating apparatus, a closed circuit including an evaporator, a compressor through which a refrigerant is circulated, a condenser interposed in said closed circuit between the evaporator and the compressor for receiving refrigerant discharged from said compressor, means for circulating air in contact with said compressor, a valve for regulating the flow of air in contact with said compressor, and thermostatic means responsive to the temperature of the compressor for actuating said valve.

10. In a refrigerating apparatus, a closed circuit including an evaporator, a compressor through which a refrigerant is circulated, a condenser interposed in said closed circuit between the evaporator and the compressor for receiving refrigerant discharged from said compressor,

- means for circulating air in contact with said compressor, a movable shielding means for varying the flow of air in contact with said compressor, and a thermostat for moving the shielding means in response to the temperature of the compressor.

11. In a refrigerating apparatus, a closed cir-,

cuit including an evaporator, a compressor through which a refrigerant is circulated, a condenser interposed in said closed circuit between the evaporator and the. compressor for receiving refrigerant discharged from said compressor, a fan for circulating air over said compressor, means for operating said fan, and thermostatic means responsive to the temperature of the compressor for preventing the flow of air over said compressor during operation of said fan.

12. In a refrigerating apparatus, a closed cir,-- cuit including an evaporator, a compressor through which a refrigerant is circulated, a condenser interposed in said closed circuit between the\ evaporator and the compressor for receiving refrigerant discharged from said compres-' sor, a fan for circulating air over said compressor and over said condenser, means for operating said fan, and thermostatic means responsive to the temperature of the compressor for preventing the flow of air over said compressor and for causing all of the air moved by the fan to flow over the condenser during operation of said fan.

13. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, means for cooling said compressor and said condenser, and means operative automatically during acertainoperation of said compressor for preventing the cooling of said compressor while permitting the cooling of said condensers 14. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, means for continuously cooling said condenser during operation of said compressor, means for preventing the cooling of said compressor during the initial operation thereof, and means automatically operative after a predetermined operation of said compressor for permitting the cooling thereof.

15. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, a body of oil in said compressor, and means for maintaining said oil at a substantially constant temperature, said means comprising means for preventing the cooling of said compressor while the temperature thereof is below a predetermined limit and for permitting the cooling thereof when the compressor is above a predetermined limit.

16. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, means for cooling said compressor and said condenser, and means for permitting the compressor to increase rapidly in temperature during initial operation thereof,

said means comprising means for preventing the cooling of said compressor during the initial operation of the compressor.

17. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, means for cooling said compressor and said condenser, and means for permitting the compressor to increase rapidly in temperature during initial operation thereof, said means comprising means for preventing the cooling of said compressor during the initial operation of the compressor, said last named means being rendered inoperative after a predetermined operation of said compressor.

18. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, means for cooling said compressor and said 'condenser, and means for permitting the compressor to increase rapidly in temperature during initial operation thereof, said means comprising means for preventing the cooling of said compressor during the initial operation of the compressor, and means responsive to the temperature of said compressor for rendering said last named means inoperative after a certain predetermined operation of the compressor.

19. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to forma closed system, means for circulating a cooling fluid medium over said compressor, means for regulating the flow of the cooling fluid medium in contact with the compressor, and means responsive to the temperature of said compressor for actuating said regulating means to permit cooling of the compressor by the cooling fluid medium.

20. In a refrigerating apparatus, a compressor, a condenser, and an evaporator connected to form a closed system, means for circulating a cooling fluid medium over said compressor, means for regulating the flow of the cooling fluid medium in contact with the compressor, and means responsive to a predetermined operation of the compressor for actuating said regu-'- lating means to permit cooling of said compressor by the cooling fluid medium.

RALPH K. MILLER. 

